The studies proposed and ongoing are for the treatment of acute leukemia and solid tumors of children. The new patient study for acute lymphocytic leukemia divides patients into pretreatment groups based on age, WBC at diagnosis, cell morhology, and the presence of CNS leukemia at diagnosis. Further randomization following successful marrow induction is for various maintenance treatment combinations for both CNS and marrow. New solid tumor studies include 1) adjuvant chemotherapy with cyclophosphamide and vincristine for extraocular retinoblastoma, 2) the use of cis-platinum and VM-26 for recurrent Stage IV neuroblastoma, 3) combined surgery, radiotherapy and chemotherapy for ovarian tumors, and 4) high-dose methotrexate, vincristine and cis-platinum for recurrent osteogenic sarcoma. New agents in Phase II studies include vindesine in tumors and recurrent leukemia, azapicyl for rhabdomyosarcoma, and betadeoxythioguanosine for refractory leukemias. The response to pneumococcal vaccine given either pre or post-splenectomy is being evaluated.